DALLAS (CBSDFW.COM) – Hundreds of Dallas classrooms don’t have full-time educators. Approximately 300 classroom teacher jobs remain unfilled. A quick search of the district’s website will show a long list of all the teaching positions available, including elementary, secondary, and specialized teaching jobs.

“Is it a major concern?” he says. “No its not, but we’re working hard to address it.”

However, teacher association leaders give three reasons why teachers are leaving. It’s because they are faced with more hours and more demands with no raises.

“When you have people taking second jobs, because they haven’t received pay increases in three-four years, people have to find ways to make their families work,” says Rena Honea from Alliance American Federation of Teachers.

For students who don’t have a permanent teacher, a district spokesperson says they have permanent substitutes. A permanent substitute is not a fill-in. They are the teacher for the year because the district hasn’t found an available, qualified educator to take the job.

The current vacancy figures are on par with the number of unfilled positions one year ago.

Dallas says its number of vacancies is normal. The district has ten thousand teachers with 300 vacancies. Compare that to Fort Worth ISD which employees five thousand teachers and lists 47 vacancies.